反应详情

3-Cyano-2,6-dichloro-4-methylpyridine (80g, 0.42 mole) was dissolved in concentrated sulfuric acid (440ml). The mixture was heated at 150° C.-170° C. with stirring for 30 minutes, cooled and poured on ice. The precipitate was filtered and washed with water. The wet filter cake was dissolved in methylene chloride, washed, neutralized with Na2Co3, dried over Na2SO4 (anhydrous), and concentrated until a white precipitate separated. Petroleum ether was added, the crystals were filtered and dried at room temperature overnight to give 83g (94%) of 2,6-dichloro-4-methyl-3-pyridinecarboxamide.

1. temperatureThe mixture was heated at 150° C.-170° C.
2. temperaturecooled
3. additionpoured on ice
4. filtrationThe precipitate was filtered
5. washwashed with water
6. dissolutionThe wet filter cake was dissolved in methylene chloride
7. washwashed
8. dry with materialdried over Na2SO4 (anhydrous)
9. concentrationconcentrated until a white precipitate
10. customseparated
11. additionPetroleum ether was added
12. filtrationthe crystals were filtered
13. customdried at room temperature overnight